Dwayne "The Rock" Johnson lost one of the two puppies he and his girlfriend adopted recently.

His French bulldog, "Brutus," passed away after eating a poisonous mushroom.

The actor turned to Instagram Tuesday to deliver a powerful message to pet owners.

"As all puppies and dogs do, he ate a mushroom while playing outside with his brother Hobbs. This mushroom happened to have a lethal toxicity and within hours it was rapidly destroying his liver and immune system to the point of no return," Johnson wrote in the caption. "I encourage all of you out there to be mindful of mushrooms in your yards, parks or anywhere outside your dogs play. What looks innocent, can be deadly to your lil' family members."

Johnson and his girlfriend, Lauren Hashian, adopted the puppies earlier this month. In an earlier Instagram post, he wrote about how the dogs jumped into his swimming pool shortly after bringing them home. While Hobbs started swimming, Brutus started sinking, leading Johnson to dive into the pool and save the pup ... hence his hashtag: #WishICouldveSavedYouOneMoreTime